Conventionally, when controlling a GUI screen at a machine in a remote location, special remote controlling software must be installed in advance on both machines.
Many of the currently available remote controlling machines are designed for operation in a variety of machine and software environments. Some machines run under different Operating Systems. Therefore, a great expenditure of effort is required to develop remote controlling software and to install it on all these machines.
In addition, since the same software versions must be installed on remotely controlled machines and the machines that exercise the remote control, a great expenditure of effort is also required to manage these machines. For example, before installing an upgrade version, the versions on all the remote controlling machines must be examined.
If remote controlling software is developed for specific platforms, the use of the software is necessarily limited to those platforms for which it is developed, and the multi-platform operations that users demand can not be implemented.
When remote controlling software is routinely installed in remote controlling machines a certain amount of memory must be permanently allocated for its storage which constitutes a barrier to the downsizing of portable remote controlling machines.
Japanese Examined Patent Publication No. Hei 8-1624 and Japanese Examined Patent Publication No. Hei 7-34188 are prior art related to the present invention. Japanese Patent Examined Publication No. Hei 8-1624 disclosed a technique whereby not only can a program run on different OSs, but also GUI sources are collectively displayed on a screen of a computer system at a remote location. Japanese Examined Patent Publication No. Hei 7-34188 discloses a computer system for supporting multi-graphics sessions comprising a central processor, a graphic terminal and a display controller processor at a remote area. These conventional techniques, however, do not resolve the above described problems because they involve the prior introduction of remote controlling software into remote controlling machines.